How to buy a 700K house with 100K in income.
Step 1. Live like a college student and keep your expenses under 20K/year.
Step 2. Pay 20K/year in taxes
http://www.richmondsavers.com/how-a-family-of-four-with-a-100000-yearly-income-pays-only-6400-in-federal-income-tax/Step 3. Save the remaining 60K/year for 2.33 years to generate 140K in savings for 20% downpayment
Step 4. Buy 700K house with 20% downpayment
A 30 year fixed mortgage for 560K costs about 2,500 per month right now, VA property tax and insurance adds under 700 to that so the total yearly cost for the house would be (2500+700)*12=38,400 which is well under the 60K/year this hypothetical person was already saving.
This is a long way of saying it would be exceptionally easy to buy a 700K home in VA with a 100K salary if you were committed to it. That being said I don't think it's that great of a goal to commit to. It would probably be better to just keep saving 60K/year and reach FI much sooner.
As for living for 20K/year in VA, that's totally possible too it just requires looking hard for a low rent spot in a shared house, biking to work and not blowing money on luxuries you don't need. I know people down there right now doing exactly this (as well as lots more people spending money they don't have).
Hope this helps.